Calculating Health Center Level Anti-Hypertensive Medication Non-Adherence Rates: Lessons Learned in New York State

The New York State Department of Health partnered with Health Center Network of New York and three member Federally Qualified Health Centers (FQHCs) to complete a pilot study examining anti-hypertensive medication (AHM) adherence among Medicaid recipients. The goals were to calculate an FQHC level non-adherence rate, the percentage of individuals prescribed an AHM who never filled the prescription, and to provide each FQHC with a list of patients who failed to fill their prescriptions.

Since there was no single system capturing both medication prescribing and dispensing data, the pilot required a parallel process of identifying individuals with diagnosed hypertension using both the FQHC electronic medical record data and Medicaid data. The pilot also required developing a comprehensive list of AHMs, a process to attribute Medicaid recipients to individual FQHCs, and a method to calculate the non-adherence rate. The project team successfully generated the list of AHMs and completed attribution. However, the attributed population using Medicaid data was 12% lower than the individuals identified using the FQHC data. As such the non-adherence rate (20%) was deemed unreliable.

The results of the pilot suggest it is not feasible to pursue calculating this measure using the method tested. It also highlights the need for using more direct methods for calculating non-adherence in a defined patient population, such as obtaining a list of patients who were prescribed AHMs to link to the Medicaid data or partnering with a health system that can provide access to both medication prescribing and dispensing data for its members.